osx man page for getsegbyname

GETSEGBYNAME(3) 					     Library Functions Manual						   GETSEGBYNAME(3)

NAME
       getsegbyname - get the segment command for the named segment

SYNOPSIS
       #include <mach-o/getsect.h>

       const struct segment_command *getsegbyname(const char *segname);

DESCRIPTION
       This  routine  returns  the  segment_command  structure for the named segment if it exists in the Mach-O (Mach object) executable getsegby-
       name(3) is linked into.	Otherwise getsegbyname(3) returns NULL.  It uses the link editor defined symbol _mh_execute_header and just  looks
       through	the load commands.  Since these are mapped into the __TEXT segment they are read-only and thus const by default.  If this is to be
       used in executables linked with -pie then the value return by the call to _dyld_get_image_vmaddr_slide(0) will need  to	be  added  to  the
       vmaddr field of the segment_command struct.

SEE ALSO
       end(3), getsectbyname(3)

Apple, Inc.							  October 3, 2008						   GETSEGBYNAME(3)